[Effect of a helium-neon laser on cellular growth: an in vitro study of human gingival fibroblasts].

For a better understanding of the clinical effects obtained with lasers of low power on oral wounds, an in vitro study was conducted on human fibroblasts obtained from a primary gingival culture in order to evaluate the effect of one or several irradiations obtained with a Helium-neon laser (632.8 nm, 10 mW). An irradiation of 10 minutes (1.2J/cm2) induced a growth acceleration of the cellular population compared to a non-irradiated control population. The greatest effect was obtained four days after treatment. Furthermore, if the cells were submitted to repeated irradiations every four days, the cellular divisions increased after each treatment. A careful interpretation of these in vitro results on healing time of oral wounds in vivo would suggest that it may be due partly to a recycling actin of low power lasers on resting cells.